Plcb4, encoding phospholipase C β4, is a membrane-associated enzyme. It is a direct signaling effector of the endothelin receptor type A (EDNRA)-Gq/11 pathway, which is crucial for establishing the identity of neural crest cells (NCCs) that form lower jaw and middle ear structures. PLCB4 is also involved in regulating several cellular behaviors like cell motility, growth, transformation, and differentiation [3].

In mice, two major subpopulations of Purkinje neurons are identified by the expression of Aldoc and Plcb4. Plcb4+ Purkinje neurons exhibit robust plasticity of gene expression in sensorimotor and learning-experienced mice. In vivo calcium imaging and optogenetic perturbation show their crucial role in associative learning. Knockout of Fgfr2 in Plcb4+ Purkinje neurons using CRISPR disrupts motor learning, revealing the importance of Plcb4+ Purkinje neurons in motor learning [1]. In pediatric acute myeloid leukemia, high PLCB4 expression is an independent risk factor of adverse overall survival and event-free survival, and is significantly higher in relapsed patients [2]. In auriculocondylar syndrome 2 (ARCND2), missense mutations in PLCB4 exert a dominant-negative interference over EDNRA signaling. F0 mouse embryos modeling one PLCB4 variant have facial defects similar to hypomorphic Ednra mouse models [3].

In conclusion, Plcb4 is important in multiple biological processes. Its role in motor learning through Plcb4+ Purkinje neurons in mice is significant. Also, its abnormal expression is associated with diseases like pediatric acute myeloid leukemia and ARCND2. Studies using gene knockout models in mice have provided valuable insights into the functions of Plcb4 in these biological processes and disease conditions.